Improvement in mounting car-doors



'ELTNITED STATES PATENT GEORGE S. KNAPP, OF CHICAGO, ILLINOIS.

IMEROVEMENT IN MOUNTING CAR-DOORS.

Specification forming part of Letters Patent No. 162,930, dated May 4,1875; application filed February 25, 1875.

To all whom it may concern:

Be it known that I, GEORGE S. KNAPP, of Chicago, in the county of Cookand State of Illinois, have invented certain Improvements in Mountingand Holding the Sliding Doors of Street-Cars, of which the following isa specification:

My invention consists in the combination of a sliding car-door onrollers, and rails having notches for the rollers to ride into, in orderto hold the door open and shut, the rollers or the rail being mademovable and pressed outward by means of a spring.

The object of the invention is, mainly, to provide a cheap, simple, andreliable arrangement for locking the sliding doors of streetcars openand shut, and, incidentally, to prevent the doors from rattling in theirframes.

When there are rollers and a guiding-rail at the top of the door, therail may be notched and forced downward upon the rollers by means of aspring, or the rail may be fixed, and the rollers forced upward againstit by means of springs.

I prefer to use rollers and rails at both the top and the bottom of thedoor, and to make all the rollers movable, and force them against therails by springs, as in such case the parts move more easily andsmoothly, and the door is also held from rattling in its frame.

In'the accompanying drawings my arrangement is clearly shown.

- Figure 1 represents an elevation of a cardoor pro edi with myimprovements, the top of the door being shown in section, in order toexpose the parts more clearly. Fig. 2 repre-.

sents a vertical section through one of the yielding rollers.

A represents the body of the car; B, the sliding door 5 C, the rollersor wheels attached to the door; D, the rail or track on which the bottomrollers travel, and E the rail on which the top rollers travel, thegeneral arrangem'ent of these parts being the same as in the cars now incommon use. The lower rail D is the notch and ho d the door from moving.

The upper rail E is also provided near one end with a notch, I, toreceive one of the top rollers when the door is shut, in order to holdthe door from opening.

The drawing represents two arrangements for causing the top roller toenter the notch in the top rail but it should be understood that onlyone arrangement will be used at a time, or, in other words, that the twoare substitutes for or equivalents of each other. One arrangementconsists in pivoting the rail or track at one end, or otherwisearranging it so that it can move vertically, and placing a spring, K,above it to force it down upon the rollers. The other arrangementconsists in mounting the rollers each in the end of a pivoted arm, L,with. a spring, M, to force the arm upward and press the roller againstthe rail. In order to keep the door from rattling, the rollers at boththe top and the bottom of the door may be thus arranged in spring oryielding bearings. The swinging arm L is mounted on a journal or pivot,0, between two plates, 0, and is slotted or recessed to receive theroller in its middle, and also provided with a strap or stirrup, whichpasses over the edge of the wheel to form a bearing for the end of thespring. The spring consists of a flat plate, having its rear end bentand seated against two studs or pivots, d and c, as shown in' Fig. 2.The three studs 0, d, and e are cast on one of the plates, and theirouter ends seated in holes in the other plate, this constructionrendering the device both strong and cheap.

The device is applied by cutting away the door at the proper point, andscrewing the two plates to its opposite faces, as shown. In

the event of the spring being broken, it is only necessary to withdrawthe door, swing the arm outward, and slip a new spring in place, afterwhich the arm is turned back in place and the door placed in position.

It is obvious that, whilein the drawing I have represented the notch tohold the door open in one rail, and the notch to hold it shut in theother rail, they may both be made in either one of the rails. It is alsoobvious that, instead of using two locking-notches, a single notch maybe used, and the front and rear rollers arranged to lock thereinalternatelyone when the door is open and the other when it is closed.

irrron By combining the rollers and the notched rails in either of theways above described, I produce a very cheap, simple, and reliable arrangement for holding the doors from opening or closing as the car rattlesalong upon the track and around the curves; and when the springs areused, I also prevent the noisy rattling of the doorsa source of greatannoyance in the ordinary cars.

Having described my invention, whatI claim 1s 1. The sliding car-doormounted on rollers,

and a notched rail or track therefor, the rollers or the rail being mademovable, and acted upon by a spring, all combined substantially asshown.

2. In combination with the sliding car-door and the notched rail ortrack, the swinging arm L, roller 0, and spring M, to operatesubstantially as shown.

GEORGE S. KNAPP.

Witnesses:

P. T. DODGE, WILLIAM ROUNSOEVILLE, Jr.

